Rotary cutter



B. H. FLYNN ROTARY CUTTER Sept; l0, 1935.

Filed Octv 25, 1954 Patented Sept. 10, 1935 UNITED STATES ATENT OFFICE 8Claims.

The invention relates to improvements `in rotary cutters havingprojecting teeth, and refers particularly to cutters of this characterdesigned primarily for hewing off rough and undulatory surfaces ofAroadways vsuch as those formed from gravel, macadam and the like.

It vis one object of the invention to provide an exceptionally simpleand inexpensive, yet an eflicient, durable and easily adjustableconstruction for holding the cutting teeth in place upon the drum orother rotary member by which they ,are carried.

Another object of the invention is to provide a cutting tooth of new andimproved form which will effectively cleave both downwardly andrearwardly through the work and will well withstand the severe strainsto which it is subjected.

Yet another object is to provide a cutting tooth which will beself-sharpening.

With the foregoing in view, the invention resides in the novel subjectmatter hereinafter described and claimed, description being accomplishedby reference to the accompanying drawing.

Fig. lis a vertical transverse `sectional view through'a rotary .cutterconstructedin accordance with the invention.

Figs. 2 and 3 are detail vertical sectional views on lines 2-2 and 3-3of Fig. 1, respectively.

Fig. 4 is a fragmentary elevation showing one of the tooth holders whenviewed in the direction indicated by the arrow A of Fig. 1.

Fig. 5 is a perspective view of one of the removable tooth-clampinglugs.

Fig. 6 is a perspective view of one of the teeth.

Fig. 7 is a detail View similar to .a portion of Fig. 1 showing thetooth released.

A preferred construction has been shown and will be rather specificallydescribed with the `understanding however, that within the scope of theinvention as claimed, variationsmay be made.

The rotary member 1 which is shown in the form of a drum, rigidlycarries Aholders `t for the teeth 9, said drum being preferably provided`with openings I0 at the inner ends `of said holders, through vwhich theteeth extend. As all of the holders are of identical construction,a-description of one will suffice. In the present showing, a curved baseplate II is provided to lie against the outer side of the drum 1, drumand base plate being secured together by bolts or the like I2. Integralwith and projecting outwardly from the base plate I I is achannel-shaped 4tooth-abutting and receiving lug I3, the channel I4 ofsaid lug being open in the direction in which the cutter rotates. `Atthe inner end of this channel, the base plate II is formed with anopening I5, one wall I6 of which constitutes an `abutment in spacedopposed relation with the closed side Illfi of the channel t4, saidopening and channel ybeing 5 in communication with each other. At itsinner end, the closed `channel side III2L is beveled as shown at I4b,providing a fulcrum AI 4 at l.the inner end of the bevel, for a purposeto appear. The depth of the channel :I4 and the ycorresponding l0dimension of the ropening I5, are .considerably greater than thethickness ofthe tooth 9, as seen most clearly in Fig. 3, and theportions of said channel and opening which are not occupied by saidtooth, receive a removable tooth-clamping l5 lug Il. The inner end ofthis lug is snugly received in the opening I5 and is provided with aface I8 which contacts with the abutment I6. The-outer end of the lug Ilis formed with lateral ears I9 disposed adjacent similar ears 29 on the20 channel-shaped tooth-receiving lug I3, and clamping 'bolts 2-I passthrough openings in the two sets of ears. As long as these bolts arevkept tight, they hold one end of the lug I1 and the other end of saidlug is vheld 4by the abutment I6 25 so that the tooth 9 is rigidly heldbut when said bolts are sufficiently `loosened (see Fig. 7), the tooth 9and the lug I'I may rock as a single unit about the fulcrum |46, therebyloosening the engagement of the lug surface I8 with the abutment 30 I6and entirely freeing the tooth to allow easy adjustment or removalthereof. When the bolts 2I are tightened, kthe tooth 9 and lug Il rockas a lsingle unit upon the fulcrum HIc to the limit allowed by the lugsurface I8 striking the abut- 35 ment I6. When this occurs, the tooth 9is not quite in contact :with the wall IIIa toward the outer end of thelatter and the final tightening of the bolts 2I therefore springs thetooth until it is drawn solidly against said wall |45. The 40 tooth isthus not only positively clamped in place but is held under tension 4andit is therefore so effectively held as to prevent it from slipping outof adjustment.

Preferably each tooth 9 is about two inches l5 wide and one-half kinchthick and to insure that the blows shall be delivered in the mostadvantageous direction, said teeth are longitudinally curved. Each toothis also .of obtuse angular form in transverse section as shown and thisformation so stiffens .the tooth .that vit ywill rwell withstand allstrains to which it is subjected. The transversely angular formation ofthe tooth also provides the .front side of said tooth with .a central,longitudinal corner z22 for cleavage engagement with the work. 'Ihepart of this corner at the extreme outer end of the tooth always strikesthe work iirst and it is thus more easy for the tooth to penetrate hardmaterial. The transversely angular form of the tooth also 'causes it tohave a tendency to laterally move the particles of gravel, rock and thelike with which it comes in contact, so that loosening of the surfacematerial of the roadway and effective hewing onc may be easilyaccomplished.

When the tooth 9 is of the obtuse angular cross section above described,the springing of said tooth caused by final tightening of the bolts 2l,tends to widen the obtuse angle and force the edges of the tooth solidlyagainst the side walls Md of the channeled lug i3.

By preference, the front side of each tooth Q, for a suitable part ofits length, is of a metal much harder than the remainder of the tooth,the hard metal being denoted at 23. This will insure not only longerlife but a self-sharpening tooth. At the opposite side of the tooth acentral hard metal portion 24 may also be provided. This will preventexcessive wear in the region of the cleavage corner 22 which alwaysstrikes the hard surface rst.

A rotary cutter of or substantially o1 the construction hereindisclosed, will eiiectively cleave both downwardly and rearwardlythrough the work as it rotates and it will be observed that thefront-to-rear dimension of each cutting blade is so slight that saidblade possesses practically no heel to either interfere with downwardpenetration of the work or to create excessive braking action retardingthe rotation of the cutter. n The blades or teeth 9 being longitudinallyadjustable in the clamps of the shaft or drum i, can be adjusted beyondsaid clamps as long as suincient portions of said blades or teeth remainto be held by said clamps, so that extreme economy is effected inoperation of the cutter.

When the various teeth 9 are of the shape herein disclosed, the holdersare of course correspondingly shaped. It will be understood however,that insofar as the tooth-holding means is concerned, it is notrestricted to use with 'curved teeth, nor with transversely angularteeth, nor is it restricted to the exact details of construction whichhave been herein disclosed for illustrative purposes.

I claim:

1. In a means for securing a cutting tooth to a rotary member, atooth-abutting lug and an abutment between which to insert the tooth,said abutment and lug being both rigidly carried by said rotary memberand being spaced apart a distance greater than the thickness of thetooth, a removable tooth-clamping lug having an inner end portioninserted between said abutment and the tooth, the outer ends of both ofsaid lugs being sufficiently wide to project laterally in oppositedirections from the tooth, and clamping bolts passing through saidprojecting portions.

2. In a means for securing a cutting tooth to a rotary member, a rigidchannel-shaped toothreceiving lug projecting beyond the periphery ofsaid rotary member and having its channel of a depth greater than thethickness of the tooth, a removable tooth-clamping lug received in saidchannel, and clamping bolts for securing the two lugs together andpositioned to straddle the tooth.

3. In a means for securing a cutting tooth to a rotary member, a rigidchannel-shaped toothreceiving lug projecting beyond the periphery ofsaid rotary member and having a channel of a depth greater than thethickness of the tooth, a removable tooth-clamping lug received in saidchannel, said rotary member being provided with an abutment abutting theouter side of said removable lug at the inner end of the latter, andclamping bolts securing the outer ends of the two lugs together andpositioned to straddle the tooth.

4. In a means for securing a cutting tooth to l a rotary member, a baseplate for attachment to the periphery of said member, said base platehaving an integral outwardly1 projecting channelshaped tooth-receivinglug and having an opening at the inner end of said lug, said opening lcommunicating with the channel of said lug to receive the inner endofthe tooth, the depth of said channel and the corresponding dimension ofsaid opening being greater than the thickness of the tooth, a removabletooth-clamping lug re- 2 ceived in said channel and having its inner endsnugly received in said opening, and clamping bolts securing the outerends of said lugs together and positioned to straddle the tooth.

5. In a means for securing a cutting tooth to 2 a rotary member, xed andmovable lugs to lie against opposite sides of the tooth, said fixed lugbeing rigidly carried by and projecting from the rotary member, clampingbolts engaged with the two lugs and positioned to draw the outer end 3of the movable lug and the tooth toward the fixed lug, said fixed lughaving a tooth-engaging fulcrum upon which the tooth and the movable lugrock as a single unit when said bolts are tighty cned, and an abutmentin ixed relation with said 3 xed lug, said abutment being disposed nearthe inner end of said movable lug in position to abut the outer side ofthe latter, said abutment being adapted to limit said rocking of saidmovable lug and tooth as said tooth is drawn completely 4 against saidfixed lug, whereby both the outer and the inner ends of the lugs arecaused to solidly grip the tooth.

6. A structure as specified in claim 5; said xed lug having a channel tosnugly receive a 4 transversely V-shaped tooth; the parts being relatedto longitudinally spring said tooth as the boits are nally tightened,thereby widening the angle of the V and forcing the edges of the toothtightly against the sides of said channel. 5

7. A rotary cutter tooth curved longitudinally, said tooth being ofobtuse angular form in transverse section throughout its length tostiften it and to provide the tooth with a work-cleaving corner, thefront portion of said tooth being 5 formed of metal much harder than theremainder of the tooth to provide a self-sharpening construction, theback of said tooth being provided with a central hardened portionpreventing eX- cessive wear of the tooth in the region of said 5work-cleaving corner.

8. A rotary cutter comprising a rotatable shaft having spaced radiallyprojecting rigidly attached tooth clamps, and longitudinally curvedcutting teeth xedly held by said clamps and longitudi- 6 nallyadjustable therein to permit projection of said teeth from said clampsuntil wear no longer permits such adjustment, each of said teeth beingof uniform width from` end to end, of uniform thickness from end to end,and of uniform ob- 7 tuse angular form in transverse section from end toend, the inside of the tooth curvature and the outside of the obtuseangle being presented inthe direction in which the 'cutter rotates.

BENJAMIN H. FLYNN.

